Wow! Well the process of unsewing will take a little time. If your mother doesn't have a specific pattern she wishes you to adhere to, then let her know what you would like to do. If there is no problem there then go for it! She gave it to you to finish...if finishing requires redesign...by all means reorganise the blocks. Who knows ? It may be the reason she just never quite got it complete. We quilters are like that sometimes. Keep us up to date on your progress. We love to see new works and recreations. :D